1. Technical Field
The present invention relates to a electric motor superior in productivity and reliability and has a winding terminal-processing structure for stator winding.
2. Background Art
FIG. 10 is a partially sectional view of a construction of a stator winding terminal process according to a conventional electric motor disclosed, for example, in the Japanese Patent Publication (unexamined) No.223843/1996. This FIG. 10 shows a cross section taken along the circumferential direction of the stator for the electric motor. In the drawing, reference numeral 1 is a stator core for the electric motor, and especially indicates a teeth portion serving as a magnetic pole. Numeral 2 is a bobbin-shaped insulator fitted on the teeth portion of the stator core 1, and numeral 3 is a flange portion arranged on the upper and lower sides of the bobbin-shaped insulator 2. Numeral 4 is a stator winding wound around the bobbin-shaped insulator 2, and numeral 4a is a terminal lead wire at the beginning or at the end of winding of the stator winding 4. Numeral 5 is a connection board serving as a winding terminal connector arranged at an end portion in axis direction of the bobbin-shaped insulator 2. The connection board 5 is composed of a printed board or laminated conductive boards, and a connection hole 5a, through which the terminal lead wire 4a passes and is fixed by soldering, is formed at a position corresponding to the terminal lead wire 4a of the stator winding 4.
Numeral 6, which is not clearly shown in FIG. 10, is a U-shaped groove formed on the winding terminal lead portion of the flange portion 3 arranged on the bobbin-shaped insulator 2. For example, by forming projections on both sides of the U-shaped groove and forming a space 7 on both sides of each projection, the terminal lead wire 4a is inserted into the U-shaped groove. Then, by heating and deforming the projection in order to fix and position the terminal lead wire 4a at a predetermined position on the flange portion 3 of the bobbin-shaped insulator 2, plural terminal lead wires 4a corresponding to the plural connection holes 5a of the connection board 5 are positioned, thereby connection work being facilitated. Thus, the terminal lead wires 4a are passed through the connection holes 5a at the same time. The mentioned conventional construction of the connection board 5 formed by laminating conductive boards provides a laminated terminal in which plural cable ways for the lead wires are formed by alternately laminating conductive boards and insulators and by arranging connecting portions at required places, as disclosed in detail, for example, in the Japanese Patent Publication (unexamined) No. 2334/1994.
As described above, in the terminal-processing method of the stator windings using the connection board 5 in the conventional electric motor, the plural terminal lead wires 4a are arranged to coincide with the plural connection holes 5a, thereby facilitating the connection work. It is, however, necessary for such a conventional method to hold and fix the connection board 5 to the stator for electric motor, and reliability such as resistance against vibration is achieved by such holding and fixing of the connection board 5. The mentioned prior arts do not always clearly describe about the holding and fixing of the connection board 5. However, for example, in case of a electric motor of large capacity, in which conductors of large diameter or straight angle lines of large cross sectional area are used as the stator windings 4. It is certainly possible to hold the connection board 5 by connecting the connection board 5 with the terminal lead wires 4a. But in case of a electric motor in which diameter of a stator winding is small or in case of a electric motor in which resistance against vibration is, it is required to arrange means for holding and fixing the connection board 5. Hence, a problem to be solved exists in that the holding and fixing means is desirably capable of easily fixing and holding the connection board 5 without occupying a large space.
The present invention was made to resolve the above-discussed problem and has an object of providing a electric motor which is superior in workability, resistant to vibration and capable of easily holding and fixing a winding terminal connector for trunk connection of each terminal lead wire of a stator winding.
A electric motor according to the invention comprises: a stator core; a rotor held by a rotary shaft with a predetermined void between the stator core and the rotor; a bobbin-shaped insulator mounted on the stator core, provided with a flange portion on at least one of outer diameter side and inner diameter side, and wound with a stator winding; a terminal holder fixed to the flange portion of the bobbin-shaped insulator and provided with a cylinder portion arranged so as to surround the rotary shaft; and annular conductors and insulating layers arranged on outer diameter side of the cylinder portion of the terminal holder and laminated alternately in axial direction; wherein the annular electric conductors are provided with a connecting portion for connecting terminal lead wires of the stator winding corresponding to lead positions of the terminal lead wires. As a result of such construction, the winding terminal connector for trunk connection of each terminal lead wire of the stator winding can be easily held and fixed. The connecting portions of the winding terminal connector are positioned fixedly with respect to the positions of the winding terminals making it easy to conduct the connecting work of the winding terminals of the stator windings. Consequently, a electric motor superior in workability and resistance to vibration is achieved.
Another electric motor according to the invention comprises: a stator core; a rotor held by a rotary shaft with a predetermined void between the stator core and the rotor; a bobbin-shaped insulator mounted on the stator core, provided with a flange portion on at least one of outer diameter side and inner diameter side, and wound with a stator winding; a terminal holder fixed to the flange portion of the bobbin-shaped insulator and provided with a cylinder portion arranged so as to surround the rotary shaft in which plural partition walls and grooves are alternately formed in radial direction on outer diameter side of the cylinder portion; and annular electric conductors stored in the grooves on outer diameter side of the cylinder portion of the terminal holder; wherein the annular electric conductors are provided with a connecting portion for connecting terminal lead wires of the stator winding corresponding to lead positions of the terminal lead wires. As a result of such construction, the winding terminal connector for trunk connection of each terminal lead wire of the stator winding can be easily held and fixed. The connecting portions of the winding terminal connector are positioned fixedly with respect to the positions of the winding terminals making it easy to conduct the connecting work of the winding terminals of the stator windings. Consequently, a electric motor superior in workability and resistance to vibration is achieved. Furthermore, since the partition walls and grooves are formed on the terminal holder in order to store the electric conductors in the grooves, and it is therefore possible to obtain a winding terminal connector capable of being easily assembled.
A further electric motor according to the invention comprises:
a stator core; a rotor held by a rotary shaft with a predetermined void between the stator core and the rotor; a bobbin-shaped insulator mounted on the stator core, provided with a flange portion on at least one of outer diameter side and inner diameter side, and wound with a stator winding; and annular conductors and insulating layers arranged on outer diameter side of the circular arc-shaped flange portions of the bobbin-shaped insulator and are laminated alternately in axial direction; wherein the annular electric conductors are provided with a connecting portion for connecting terminal lead wires of the stator winding corresponding to lead positions of the terminal lead wires. As a result of such construction, the winding terminal connector for trunk connection of each terminal lead wire of the stator winding can be easily held and fixed. The connecting portions of the winding terminal connector are positioned fixedly with respect to the positions of the winding terminals making it easy to conduct the connecting work of the winding terminals of the stator windings. Consequently, a electric motor superior in workability and resistance to vibration is achieved. Furthermore, since the bobbin-shaped insulators wound with the stator winding hold directly the electric conductors and insulating layers, thereby making a winding terminal connector, it is possible to obtain a small-sized electric motor.
It is also preferable that the annular electric conductors and the insulating layers laminated alternately are held either by a holding portion of the terminal holder or by the bobbin-shaped insulator through an elastic member. As a result of such construction, variation or irregularity in dimensions is absorbed and resistance to vibration is improved.
It is also preferable that the elastic member is formed integrally with the terminal holder or the bobbin-shaped insulator.
It is also preferable that the flange portion of the bobbin-shaped insulator has an engaging window, the terminal holder has engaging claws for engaging with the engaging window, and the terminal holder is held by and fixed to the bobbin-shaped insulator by engaging the engaging claws with the engaging window. As a result, the winding terminal connector is securely fixed to the stator of the electric motor.
It is also preferable that the flange portion of the bobbin-shaped insulator and a mounting portion of the terminal holder are provided with screw portions, and the terminal holder is held by and fixed to the bobbin-shaped insulator by fitting the screw portions with screws. As a result of such construction, the winding terminal connector is securely fixed to the stator of the electric motor.